From 6ec3938cff95fe792a05fdf4ba14f92977e5e31d Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Mon, 15 Oct 2018 09:18:24 -0600 Subject: [PATCH] ataflop: convert to blk-mq This driver is already pretty broken, in that it has two wait_events() (one in stdma_lock()) in request_fn. Get rid of the first one by freezing/quiescing the queue on format, and the second one by replacing it with stdma_try_lock(). The rest is straightforward. Compile-tested only and probably incorrect. Cc: Laurent Vivier Signed-off-by: Omar Sandoval Converted to blk_mq_init_sq_queue() Signed-off-by: Jens Axboe --- drivers/block/ataflop.c | 173 +++++++++++++++++----------------------- 1 file changed, 71 insertions(+), 102 deletions(-) diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c index 0144d598ac47..f88b4c26d422 100644 --- a/drivers/block/ataflop.c +++ b/drivers/block/ataflop.c @@ -66,7 +66,7 @@ #include #include #include -#include +#include #include #include #include @@ -81,7 +81,6 @@ static DEFINE_MUTEX(ataflop_mutex); static struct request *fd_request; -static int fdc_queue; /* * WD1772 stuff @@ -300,6 +299,7 @@ static struct atari_floppy_struct { struct gendisk *disk; int ref; int type; + struct blk_mq_tag_set tag_set; } unit[FD_MAX_UNITS]; #define UD unit[drive] @@ -379,9 +379,6 @@ static int IsFormatting = 0, FormatError; static int UserSteprate[FD_MAX_UNITS] = { -1, -1 }; module_param_array(UserSteprate, int, NULL, 0); -/* Synchronization of FDC access. */ -static volatile int fdc_busy = 0; -static DECLARE_WAIT_QUEUE_HEAD(fdc_wait); static DECLARE_COMPLETION(format_wait); static unsigned long changed_floppies = 0xff, fake_change = 0; @@ -441,7 +438,6 @@ static void fd_times_out(struct timer_list *unused); static void finish_fdc( void ); static void finish_fdc_done( int dummy ); static void setup_req_params( int drive ); -static void redo_fd_request( void); static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long param); static void fd_probe( int drive ); @@ -459,8 +455,11 @@ static DEFINE_TIMER(fd_timer, check_change); static void fd_end_request_cur(blk_status_t err) { - if (!__blk_end_request_cur(fd_request, err)) + if (!blk_update_request(fd_request, err, + blk_rq_cur_bytes(fd_request))) { + __blk_mq_end_request(fd_request, err); fd_request = NULL; + } } static inline void start_motor_off_timer(void) @@ -706,7 +705,6 @@ static void fd_error( void ) if (SelectedDrive != -1) SUD.track = -1; } - redo_fd_request(); } @@ -724,14 +722,15 @@ static void fd_error( void ) static int do_format(int drive, int type, struct atari_format_descr *desc) { + struct request_queue *q = unit[drive].disk->queue; unsigned char *p; int sect, nsect; unsigned long flags; + int ret; - DPRINT(("do_format( dr=%d tr=%d he=%d offs=%d )\n", - drive, desc->track, desc->head, desc->sect_offset )); + blk_mq_freeze_queue(q); + blk_mq_quiesce_queue(q); - wait_event(fdc_wait, cmpxchg(&fdc_busy, 0, 1) == 0); local_irq_save(flags); stdma_lock(floppy_irq, NULL); atari_turnon_irq( IRQ_MFP_FDC ); /* should be already, just to be sure */ @@ -740,16 +739,16 @@ static int do_format(int drive, int type, struct atari_format_descr *desc) if (type) { if (--type >= NUM_DISK_MINORS || minor2disktype[type].drive_types > DriveType) { - redo_fd_request(); - return -EINVAL; + ret = -EINVAL; + goto out; } type = minor2disktype[type].index; UDT = &atari_disk_type[type]; } if (!UDT || desc->track >= UDT->blocks/UDT->spt/2 || desc->head >= 2) { - redo_fd_request(); - return -EINVAL; + ret = -EINVAL; + goto out; } nsect = UDT->spt; @@ -788,8 +787,11 @@ static int do_format(int drive, int type, struct atari_format_descr *desc) wait_for_completion(&format_wait); - redo_fd_request(); - return( FormatError ? -EIO : 0 ); + ret = FormatError ? -EIO : 0; +out: + blk_mq_unquiesce_queue(q); + blk_mq_unfreeze_queue(q); + return ret; } @@ -819,7 +821,6 @@ static void do_fd_action( int drive ) else { /* all sectors finished */ fd_end_request_cur(BLK_STS_OK); - redo_fd_request(); return; } } @@ -1224,7 +1225,6 @@ static void fd_rwsec_done1(int status) else { /* all sectors finished */ fd_end_request_cur(BLK_STS_OK); - redo_fd_request(); } return; @@ -1382,8 +1382,6 @@ static void finish_fdc_done( int dummy ) local_irq_save(flags); stdma_release(); - fdc_busy = 0; - wake_up( &fdc_wait ); local_irq_restore(flags); DPRINT(("finish_fdc() finished\n")); @@ -1473,59 +1471,34 @@ static void setup_req_params( int drive ) ReqTrack, ReqSector, (unsigned long)ReqData )); } -/* - * Round-robin between our available drives, doing one request from each - */ -static struct request *set_next_request(void) +static blk_status_t ataflop_queue_rq(struct blk_mq_hw_ctx *hctx, + const struct blk_mq_queue_data *bd) { - struct request_queue *q; - int old_pos = fdc_queue; - struct request *rq = NULL; - - do { - q = unit[fdc_queue].disk->queue; - if (++fdc_queue == FD_MAX_UNITS) - fdc_queue = 0; - if (q) { - rq = blk_fetch_request(q); - if (rq) { - rq->error_count = 0; - break; - } - } - } while (fdc_queue != old_pos); - - return rq; -} - + struct atari_floppy_struct *floppy = bd->rq->rq_disk->private_data; + int drive = floppy - unit; + int type = floppy->type; -static void redo_fd_request(void) -{ - int drive, type; - struct atari_floppy_struct *floppy; + spin_lock_irq(&ataflop_lock); + if (fd_request) { + spin_unlock_irq(&ataflop_lock); + return BLK_STS_DEV_RESOURCE; + } + if (!stdma_try_lock(floppy_irq, NULL)) { + spin_unlock_irq(&ataflop_lock); + return BLK_STS_RESOURCE; + } + fd_request = bd->rq; + blk_mq_start_request(fd_request); - DPRINT(("redo_fd_request: fd_request=%p dev=%s fd_request->sector=%ld\n", - fd_request, fd_request ? fd_request->rq_disk->disk_name : "", - fd_request ? blk_rq_pos(fd_request) : 0 )); + atari_disable_irq( IRQ_MFP_FDC ); IsFormatting = 0; -repeat: - if (!fd_request) { - fd_request = set_next_request(); - if (!fd_request) - goto the_end; - } - - floppy = fd_request->rq_disk->private_data; - drive = floppy - unit; - type = floppy->type; - if (!UD.connected) { /* drive not connected */ printk(KERN_ERR "Unknown Device: fd%d\n", drive ); fd_end_request_cur(BLK_STS_IOERR); - goto repeat; + goto out; } if (type == 0) { @@ -1541,23 +1514,18 @@ repeat: if (--type >= NUM_DISK_MINORS) { printk(KERN_WARNING "fd%d: invalid disk format", drive ); fd_end_request_cur(BLK_STS_IOERR); - goto repeat; + goto out; } if (minor2disktype[type].drive_types > DriveType) { printk(KERN_WARNING "fd%d: unsupported disk format", drive ); fd_end_request_cur(BLK_STS_IOERR); - goto repeat; + goto out; } type = minor2disktype[type].index; UDT = &atari_disk_type[type]; set_capacity(floppy->disk, UDT->blocks); UD.autoprobe = 0; } - - if (blk_rq_pos(fd_request) + 1 > UDT->blocks) { - fd_end_request_cur(BLK_STS_IOERR); - goto repeat; - } /* stop deselect timer */ del_timer( &motor_off_timer ); @@ -1569,22 +1537,13 @@ repeat: setup_req_params( drive ); do_fd_action( drive ); - return; - - the_end: - finish_fdc(); -} - - -void do_fd_request(struct request_queue * q) -{ - DPRINT(("do_fd_request for pid %d\n",current->pid)); - wait_event(fdc_wait, cmpxchg(&fdc_busy, 0, 1) == 0); - stdma_lock(floppy_irq, NULL); - - atari_disable_irq( IRQ_MFP_FDC ); - redo_fd_request(); + if (bd->last) + finish_fdc(); atari_enable_irq( IRQ_MFP_FDC ); + +out: + spin_unlock_irq(&ataflop_lock); + return BLK_STS_OK; } static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode, @@ -1662,7 +1621,6 @@ static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode, /* what if type > 0 here? Overwrite specified entry ? */ if (type) { /* refuse to re-set a predefined type for now */ - redo_fd_request(); return -EINVAL; } @@ -1730,10 +1688,8 @@ static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode, /* sanity check */ if (setprm.track != dtp->blocks/dtp->spt/2 || - setprm.head != 2) { - redo_fd_request(); + setprm.head != 2) return -EINVAL; - } UDT = dtp; set_capacity(floppy->disk, UDT->blocks); @@ -1989,6 +1945,10 @@ static const struct block_device_operations floppy_fops = { .revalidate_disk= floppy_revalidate, }; +static const struct blk_mq_ops ataflop_mq_ops = { + .queue_rq = ataflop_queue_rq, +}; + static struct kobject *floppy_find(dev_t dev, int *part, void *data) { int drive = *part & 3; @@ -2002,6 +1962,7 @@ static struct kobject *floppy_find(dev_t dev, int *part, void *data) static int __init atari_floppy_init (void) { int i; + int ret; if (!MACH_IS_ATARI) /* Amiga, Mac, ... don't have Atari-compatible floppy :-) */ @@ -2012,13 +1973,19 @@ static int __init atari_floppy_init (void) for (i = 0; i < FD_MAX_UNITS; i++) { unit[i].disk = alloc_disk(1); - if (!unit[i].disk) - goto Enomem; + if (!unit[i].disk) { + ret = -ENOMEM; + goto err; + } - unit[i].disk->queue = blk_init_queue(do_fd_request, - &ataflop_lock); - if (!unit[i].disk->queue) - goto Enomem; + unit[i].disk->queue = blk_mq_init_sq_queue(&unit[i].tag_set, + &ataflop_mq_ops, 2, + BLK_MQ_F_SHOULD_MERGE); + if (IS_ERR(unit[i].disk->queue)) { + ret = PTR_ERR(unit[i].disk->queue); + unit[i].disk->queue = NULL; + goto err; + } } if (UseTrackbuffer < 0) @@ -2035,7 +2002,8 @@ static int __init atari_floppy_init (void) DMABuffer = atari_stram_alloc(BUFFER_SIZE+512, "ataflop"); if (!DMABuffer) { printk(KERN_ERR "atari_floppy_init: cannot get dma buffer\n"); - goto Enomem; + ret = -ENOMEM; + goto err; } TrackBuffer = DMABuffer + 512; PhysDMABuffer = atari_stram_to_phys(DMABuffer); @@ -2063,7 +2031,8 @@ static int __init atari_floppy_init (void) config_types(); return 0; -Enomem: + +err: do { struct gendisk *disk = unit[i].disk; @@ -2072,12 +2041,13 @@ Enomem: blk_cleanup_queue(disk->queue); disk->queue = NULL; } + blk_mq_free_tag_set(&unit[i].tag_set); put_disk(unit[i].disk); } } while (i--); unregister_blkdev(FLOPPY_MAJOR, "fd"); - return -ENOMEM; + return ret; } #ifndef MODULE @@ -2124,11 +2094,10 @@ static void __exit atari_floppy_exit(void) int i; blk_unregister_region(MKDEV(FLOPPY_MAJOR, 0), 256); for (i = 0; i < FD_MAX_UNITS; i++) { - struct request_queue *q = unit[i].disk->queue; - del_gendisk(unit[i].disk); + blk_cleanup_queue(unit[i].disk->queue); + blk_mq_free_tag_set(&unit[i].tag_set); put_disk(unit[i].disk); - blk_cleanup_queue(q); } unregister_blkdev(FLOPPY_MAJOR, "fd"); -- 2.39.5